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Introduc.on  to  Databases  

Dr.  Jeff  Pi9ges  ITEC  110  

Objec.ve  

•  Provide  an  overview  of  database  systems    

•  What  is  a  database?    

•  Why  are  databases  important?    

•  What  careers  are  available  in  the  Database  field?    

•  How  do  I  learn  more  about  databases?      

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What is a Database?

A collection of persistent data that can be shared

and interrelated

Mannino, Database Design, Application Development, & Administration, 3rd Edition

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What is a Mission Critical System or Application?

A system or application that must be operational

for a company to function.

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Examples of Mission Critical Systems

•  Email •  Point of Sale •  Order Processing •  Warehouse Management Systems •  Financial Systems

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Mission Critical Business system that does not require a database

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DBMS: Database Container

DBMS

Database

Database Database

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Oracle Corporation

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Why Databases? "

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In the Beginning…

Customer Program 1

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Program-Data Dependence

DATA DIVISION. FILE SECTION. FD EMP-FILE LABEL RECORDS ARE OMITTED. 01 EMP-RECORD. 05 EMP-NUMBER PIC 9(4). 05 EMP-LASTNAME PIC X(11). 05 EMP-FIRSTNAME PIC X(11). 05 EMP-SEX PIC X(1). 05 EMP-DEPTID PIC X(4). 05 EMP-SALARY PIC 9(8).

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File System Model

Cust

Inv

Sales

Program 1

Program 2

Program 4

Program 3

Program 5

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Problems with File System Model

•  Changes to file structure or file location effect many programs causing high maintenance costs.

•  Data in various and sometimes proprietary data formats. •  File Indexes were easily corrupted if not open during data entry,

updates, or deletes. •  All Data validation was completely dependent on all application

programs. •  All Data security was completely dependent on all application

programs. •  Efficient Multi-application / multi-user access to the same file(s)

required strict adherence to agreed upon locking strategies. •  Integrated backup and recovery of hundreds of data files is

difficult to control. •  Tendency for redundant data to enter various data files.

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The Solution: DBMS

File 1

File X

Program 1

Program 2

Program 4

Program 3

Program 5

Cust

Sales

Inv

•  • 

• 

DBMS

SQL

Changes to file structure or file location are transparent to application programs. Maintenance costs drop dramatically.

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The Solution: DBMS

File 1

File X

Program 1

Program 2

Program 4

Program 3

Program 5

Cust

Sales

Inv

•  • 

• 

DBMS

SQL

All data is available through a standard SQL interface and related, industry standard query and reporting tools.

Q & R tools

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The Solution: DBMS

File 1

File X

Program 1

Program 2

Program 4

Program 3

Program 5

Cust

Sales

Inv

•  • 

• 

DBMS

SQL

All Data validation rules are defined within the DBMS and enforced independently of application program logic.

Con

stra

ints

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The Solution: DBMS

File 1

File X

Program 1

Program 2

Program 4

Program 3

Program 5

Cust

Sales

Inv

•  • 

• 

DBMS

SQL

Primary responsibility for Data security is now handled by the DBMS providing user based security down to the attribute level.

Users

Grants

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The Solution: DBMS

File 1

File X

Program 1

Program 2

Program 4

Program 3

Program 5

Cust

Sales

Inv

•  • 

• 

DBMS

SQL

All aspects of multi-user access are handled by the DBMS.

• Locks • Rollbacks • Commits • Transactions

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The Solution: DBMS

File 1

File X

Program 1

Program 2

Program 4

Program 3

Program 5

Cust

Sales

Inv

•  • 

• 

DBMS

SQL

A comprehensive, integrated solution to backup and recovery is provided.

Backup R

ecov

ery

Log Files

Recovery

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The Solution: DBMS

File 1

File X

Program 1

Program 2

Program 4

Program 3

Program 5

Cust

Sales

Inv

•  • 

• 

DBMS

SQL

A single normalized conceptual model of all data managed by a database administrator (DBA) eliminating redundant and therefore inconsistent data.

Schema

DBA

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Relational Model

•  Relational model is based on tables with rows and columns –  Intuitive

•  RDBMS is based on extensive theory – Relational Algebra

•  Commercial database vendors have implemented a subset of the relational model, often with proprietary extensions

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Relations and Tuples

EMPID LNAME FNAME DEPT PHONE SALARY

23 Jones Mark ITR 555-1087 45000

25 Smith Sara FINC 555-2222 49000

26 Billings David ACTG 555-4356 42000

31 Dance Ivanna ACTG 444-4887 60000

32 Jones Mary ITR 555-8745 70000

35 Barker Bob ACTG 555-6565 44000

36 Woods Robin ITR 555-9812 90000

37 Jones Mary FINC 555-1234 56000

Employees Table SEX

M

F

M

F

F

M

M

F

Challenges  

•  Databases  are  conceptually  simple      •  Databases  and  Opera.ng  Systems  are  large,  mul.-­‐user  systems  that  face  nearly  every  major  challenge  of  compu.ng  systems    

 •  Many  students  report  that  databases  are  far  more  interes.ng  and  challenging  than  expected    

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Database  Jobs  

1.  Database  Developer    

2.  Database  Administrator  (DBA)    

3.  Data  /  Business  Analyst    

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Database  Developer  

•  Develop  informa.on  systems  and  database  applica.ons    

 •  Database  engineers  work  exclusively  within  the  database    

 •  SoYware  engineers  may  design  and  develop  end-­‐to-­‐end  systems    

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Concentra.ons  and  Cer.fica.ons  

•  Database    

•  SoYware  Engineering    

•  Web  Development    

•  Security  Cer.ficate    

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Database  Development  

•  Query  the  database  using  SQL    •  Data  Modeling    •  Design  and  develop  physical  database  objects    •  Design  transac.ons    •  Develop  stored  procedures  and  triggers    

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SQL  

•  SQL:  Structured  Query  Language    •  Specify  data  to  be  retrieved  from  the  database    

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SELECT  name,  gpa  FROM    Students  WHERE  rank  =  ‘SR’  AND  major  =  ‘ITEC’  ORDER  BY  gpa  DESC    

Find  a  Friend  on  Facebook  

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First  

City  

Last   School  

State  

SELECT  first,  last,  city,  state,  school  FROM    Users    WHERE  first  =  ?  AND  last  =  ?  AND  school  =  ?                AND  city  =  ?  AND  state  =  ?;      

Data  Modeling  

•  Conceptual  representa.on  of  how  data  is  organized  in  the  database    

 •  En.ty  Rela.onship  Diagrams  are  similar  to  object-­‐oriented  data  models    

 •  An  en.ty  usually  represents  a  person,  place,  or  thing    

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Application Schema

A standard Oracle application typically starts with 250 - 500 pre-defined tables

Views  

•  Database  tables  are  created  to  store  data  efficiently  and  effec.vely  –  NOT  user  friendly    

•  Views  are  created  on  top  of  the  tables    •  Views  increase  usability  by  simplifying  the  schema  and  crea.ng  objects  that  are  meaningful  to  business  users    

•  Views  enforce  security  by  restric.ng  access  to  rows  and  columns    

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Three Schema Architecture

External Level

View 1 View n View 2

Logical Level

Conceptual Schema

Physical Level

Internal Schema

Database  Administrator  (DBA)  

•  Install  and  maintain  database  systems    

•  Design  and  implement  database  security    

•  Manage  user  accounts  and  permissions    

•  Backup  and  recover  data    •  Tune  and  op.mize  performance      

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Concentra.ons  and  Cer.ficates  

•  Database    •  Security  Cer.ficate    

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Physical  Design  

•  Database  developers  and  analysts  work  with  the  conceptual  database    

 •  Database  Administrators  work  with  the  physical  database    – Data  files    – Disk  storage      – Servers  and  other  hardware    

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24/7  Up.me  

•  Enterprise  database  systems  are  usually  available  24  hours  a  day,  7  days  a  week    

 

•  This  requires  fault  tolerant  systems    

– Redundant  components    

– Redundant  data  storage    

•  The  DBA  must  recover  from  failure    

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Data  Analyst  

•  Analyze  data  to  help  people  and  organiza.ons  make  be9er  decisions    

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Concentra.ons  and  Cer.ficates  

•  Database    •  Computer  Science    •  Informa.on  Systems    

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Going Global

The following slides were presented

by Paul Grossman at the

February 2009 NCTC Technology & Toast

ExportVirginia.org

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THE REAL WORLD

POPULATION

Source: www.world mapper.org 42

THE REAL WORLD

CONTAINER PORTS

Source: www.world mapper.org

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THE REAL WORLD

HIGH TECH EXPORTS1990

Source: www.world mapper.org 44

THE REAL WORLD

HIGH TECH EXPORTS 2002

Source: www.world mapper.org

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THE REAL WORLD

HIGH TECH EXPORTS 2002

Source: www.world mapper.org 46

What If

•  You could view your business like these maps of the world?

•  You could identify trends and compare

your business to your competitors with respect to the market?

•  You could see opportunities?

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Business Intelligence

A set of tools and techniques

that help people and companies

make better decisions

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BI Technologies •  Data Warehousing •  OLAP •  Executive Dashboards •  Data Mining •  Decision Support Systems (DSS) •  Expert Systems

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Drowning in Data Starving for Information

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Data Warehousing

Data

Information Assets

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Warehouses Report the Facts

•  Who •  What •  When •  Where •  Why

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OnLine  Analy.cal  Processing  OnLine Analytical Processing

The process of slicing and dicing data: – Drill Down – Drill Up – Drill Across

OLAP

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OLAP Example

Analyze quarterly sales

– Expected 10% increase in revenue – Realized a 9.5% increase – Why did quarterly revenue fall short

of expectations?

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Investigate the Facts

•  Why were sales short of expectations? •  When – Time Dimension

– Compare sales in Q1 2005 to Q1 2006

•  What -- Product Dimension •  Who -- Customer Dimension

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Dimensional Model

Time Day Week Month Quarter Year Weekend Holiday

Product Department Category Brand Weight

Customer Age Gender Status Income

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When

Time Dimension

Year Quarter

Month Week

Day

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Time Dimension

2005 Q1

Q2

Q3

Q4

Q1

Q2

2006

T ime

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Sales by Quarter

Q1 ‘05 Q1 ‘06

$100

$109.5 é 9.5%

Quarter

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Drill Down into Department

-  Clothes -  Electronics -  Books

What

Product Hierarchy

Category

Brand

Product

Department

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Product Dimension

2  0  0  5   Q  1  Q  2  

Q  3  

Q  4  

Q  1  

Q  2  

2  0  0  6  

T  i  m  e  

P  r  o  d  u  c  t  

B  o  o  k  s  E  l  e  c  t  r  o  n  i  c  s  C  l  o  t  h  e  s  

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Sales By Department

Clothes Electronics Books

10%

10.3% 10.4% 8.7%

Q1 ‘06

Q1 ‘06

Q1 ‘06

Dept

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Drill Down into Books

Product Hierarchy

Category

Brand

Product

Department

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Product Dimension

2005 Q1

Q2

Q3

Q4

Q1

Q2

2006

Time

Product

BooksElectronicsClothes

Novels

Textbooks

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Sales by Book Category

10%

Novels

10.6%

Textbooks

Q1 ‘06

6.8%

Q1 ‘06

Category

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Who

•  Age group •  Gender •  Marital status •  Occupation •  Annual income

Customer Dimension

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Drill Down into Age Group

10%

25 - 45

10.9%

Q1 ‘06

4.2%

Q1 ‘06

Under 25 46 - 65

10.4%

Q1 ‘06

Over 65

11.1%

Q1 ‘06

Age

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Customer Dimension

2005 Q1

Q2

Q3

Q4

Q1

Q2

2006

Time

Product

BooksElectronicsClothes

Customer

Under 25

Over 65

25 - 45

46 - 65

Novels

Textb

ooks

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Analysis

•  Sales of textbooks to customers under 25 (students) fell well short of expectations

•  What should the company do? •  Increase advertisements and incentives

for textbooks to students

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Executive Dashboards

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Monitoring Your Business

•  Management by Objective (MBO) – Sales -- revenue targets – Customer Support -- customer satisfaction

•  Key Performance Indicators (KPI) – Measure performance

•  Dashboard Displays KPIs – Color coded Green Yellow Red

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Example Dashboard

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Clicking on Virginia drills down to Inventory by City

Alexandria Richmond Roanoke

Inventory Level

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Data Mining

Knowledge Discovery

Identify patterns in your data

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Market Basket Analysis Identify items purchased together

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Data Mining Tasks

•  Predict – Churn Analysis –  Increase response rate

•  Estimate – Customer satisfaction and renewal rate

•  Classify – Fraud Detection

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Business Intelligence Systems

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Enterprise Architecture

Production Systems

Extract Load

Transform

Data Warehouse

Reporting OLAP GUI

Data Mining External

Data Sources

Database  Classes  

•  Database  I  (340)    – Database  Development      

•  Database  II    (441)  – Database  Administra.on      

•  Data  Warehousing,  Mining,  Repor.ng    (442)    – Data  Analysis    

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